Method for Producing a Casting Core and a Casting Core

ABSTRACT

A method for the production of a casting core is provided. The method includes preparing a mold which has at least one cavity and at least one filling opening which is fluidically connected to the cavity, introducing a liquid, hardenable salt molding material into the cavity via the filling opening, and at least partial hardening of the salt molding material introduced into the cavity to form a hollow body produced from hardened salt molding material, the hollow body having at least one hollow space of the casting core which is delimited by the hardened salt molding material. The hollow space of the casting core is closed on all sides by means of the salt molding material introduced into the cavity. A casting core is also provided.

BACKGROUND AND SUMMARY OF THE INVENTION

The invention relates to a method for the production of a casting core,in particular for metal casting, as well as a casting core, inparticular for metal casting.

In casting technology, it has been shown that hollow die casting parts,in particular hollow aluminum die casting parts, having low wallstrengths with the aid of lost core setters often cannot beautomatically produced to be dimensionally stable, in particular due tolacking core mounting and handling concepts. Such hollow aluminumcomponents are, however, advantageous in that they are light and theyare quick and cost-effective to produce.

It has been shown that the use of sand cores is not expedient since theyare not suitable with regard to strength, surface quality anddimensional stability for the production of thin-walled, complexcomponents, in particular structural components for vehicleconstruction. Furthermore, high pressures should be observed when usingcasting cores in the die casting method, with which high pressures theliquid casting material is introduced into the die casting mold, inwhich at least one casting core is located. These high pressures, whichcan be up to 800 bar, subject the casting core to high loads during diecasting which a sand core cannot withstand.

A method for the production of a casting core, in particular for metalcasting, as well as such a casting core, can be taken as known from DE10 2012 022 102 A1. A mold is provided for the method which has at leastone cavity and at least one filling opening which is fluidicallyconnected to the cavity. A liquid, hardenable salt molding material isintroduced into the cavity via the filling opening; the casting core isthus a cast salt core. The salt molding material introduced into thecavity is at least partially hardened, such that a hollow body producedfrom the hardened salt molding material having at least one hollow spaceof the casting core delimited by the hardened salt molding materialresults.

In this known method, the casting core still has one opening after thehardening of the salt molding material in the region of the fillingopening, the opening leading on one side into the hollow space and onthe other side into the surroundings of the casting core. In a furtherstep, the casting core or its hollow space is filled with a solidgranulate or a solid powder, by means of which the opening is closed.Alternatively, the hollow space is filled with a fluid. The opening isclosed by filling the hollow space with the granulate or fluid such thatno liquid casting material can enter into the hollow space of thecasting core during the die casting method. However, filling the hollowspace and the closing of the opening caused by this represent anadditional process step which is usually required, however, in order toseal the hollow space.

A suitable salt molding material for the production of a lost castingcore in a die casting method is, for example, known from EP 2 647 451A1.

Finally, DE 10 2011 105 389 A1 discloses a casting tool, in particularfor the production of a cylinder crankhouse of a combustion engine. Thecasting tool includes a first part of a die casting mold of the castingtool and a core arranged on the first part, the core being positioned onthe first part by a fixed bearing. It is thereby provided that the coreis positioned on the first part by an additional floating bearing tobalance thermal expansions of the core.

The object of the present invention is therefore to create a method anda casting core of the type cited above, by means of which a particularlysimple, quick and cost-effective production of the casting core can beachieved.

In order to create a method for the production of a casting core, bymeans of which a particularly simple, quick and cost-effectiveproduction of the casting core can be achieved, it is provided accordingto the invention that the hollow space of the casting core is closed onall sides by means of the molding material introduced into the cavity.By means of the method according to the invention, it is thus possibleto produce a completely closed hollow casting core having a defined wallstrength by casting, wherein the hollow casting core, i.e., the castingcore, can be produced without separate sealing measures to be sealed fordie casting and, for example, can be cast around as a lost core in a diecasting tool, in particular in an aluminum die casting tool without aliquid casting material, which is introduced into the die casting tool,entering into the hollow space of the casting core. Since the hollowspace is closed on all sides, i.e., completely, by means of the saltmolding material, the hollow space of the casting core must not befilled with a material or liquid which is different from the saltmolding material. The time and material requirements for the productionof the casting core can thereby be kept particularly low. Since thecasting core is produced with a large volume and hollowly as a cast saltcore for die casting, in particular for aluminum die casting, on onehand, a large hollow space can be achieved in a casting component, inparticular in an aluminum casting component by means of the castingcore. On the other hand, the hollow, cast salt core has the advantagethat it can be produced with a low molding material requirement.Furthermore, in comparison to a solid casting core, only a small amountof salt must be washed out of the die casting component after casting. Afurther advantage is that the core of the cast die casting component canbe removed in a particularly simple manner since the casting core issoluble in water as a result of it being produced from salt. The castingcore can thereby be washed out of the die casting component in a simplemanner using water after producing the die casting component.

Since the hollow space is completely closed, the hollow body has acompletely closed crust with a defined wall strength. A high compressivestrength of the core can be ensured by correspondingly adjusting thewall thickness of the salt crust, such that the casting core can, forexample, also bear high pressures during die casting without damageoccurring. A further advantage of the completely closed crust is thatthe casting core can be used directly as a die casting core. This meansthat, after producing the casting core, no further processing steps arerequired, in particular, to close the hollow space. The only possiblereworking required consists in separating undesired or unnecessarycasting runners from the hollow body. Moreover, the casting core can becast to be near-net-shape, in particular with a tolerance in a rangefrom 0.1 to 0.5 millimeters and removed from the mold. This tolerancerange from 0.1 millimeters inclusive to 0.5 millimeters inclusivethereby relates to the deviation of the end contour of the cast castingcore from an ideal contour, for example, according to the design drawingof the casting core. This means that the casting core can be used as acasting core in a casting mold, in particular a die casting mold afterits production without subsequent surface treatments.

It has been shown to be furthermore advantageous when still liquid saltmolding material, i.e., a liquid molten material from the salt moldingmaterial, and a high pressure are maintained during cooling and duringhardening of the salt molding material in the hollow space. As a result,the danger of cracks arising in the crust during cooling when producingthe casting core by shrinkage is kept particularly low. This embodimentis based on the knowledge that salts have a very high thermal expansion.The thermal expansion can be approximately twice as high as the thermalexpansion of aluminum. Fine hairline cracks arising during cooling byshrinkage are uncritical at first. However, during die casting, inparticular during aluminum die casting, pressures of up to 800 bar acton the casting core, wherein hairline cracks represent potentialbreaking points. However, the risk of cracks arising can be kept low byholding liquid molten material in the hollow space and by adjusting ahigh pressure in the hollow space during hardening.

In the context of the method, the casting core is, for example, moved bymeans of a gripper of a robot, preferably three-dimensionally, in orderto achieve an at least substantially even wall strength of the hollowbody. For this purpose, the mold, by means of which the casting core isproduced, can be moved. Alternatively, it is possible to remove and movethe casting core out of the mold by means of a gripper.

In the context of the method, it can be provided that the liquid saltmolding material can be introduced into the mold and held there for 10seconds, at approximately 700 degrees Celsius and approximately 50degrees above the solidus temperature of the salt molding material. Thesubsequent molding of the casting core lasts for approximately 45 to 120seconds. The molding preferably lasts for a maximum of 120 seconds. Ithas been shown, in particular, that in the event of a longer moldingduration, the casting core can crack due to shrinkage constraint. If thecasting core or its hollow body has a high wall strength, i.e., if thehollow body is formed as a particularly thick shell, then the castingcore has particularly high heat isolation.

Hollow aluminum die casting components can be produced by means of thecasting core, wherein such hollow aluminum die casting components areparticularly light. The production of such aluminum die castingcomponents can thereby be achieved in a cost-effective manner by meansof the casting core.

Sand cores are usually used to produce hollow spaces in aluminumcomponents. However, these do not withstand the high pressures duringdie casting. However, in order to be able to produce particularlythin-walled components which are light and thus are used in particularas structural components in vehicle construction, die casting must beused. Salt cores are particularly advantageous as casting cores for usein aluminum die casting since they have a good, i.e., even, surface andhigh stability. However, these salt cores are required to be able to beremoved in a simple manner from the produced aluminum die castingcomponent and to be able to be produced in a cost-effective manner.

It is thereby known to produce salt cores from pure sodium chloride(NaCl), wherein these salt cores are produced by pressing and baking.However, these salt cores only have a limited load capacity, such thatthey can carry damage when used in a die casting method.

A higher load capacity can be achieved with cast salt cores. The methodaccording to the invention now enables particularly cost-effectiveproduction of a cast salt core since additional sealing measures toclose the hollow space can be avoided at least in the region of thefilling opening. For example, it is possible to use a casting coreproduced according to the method according to the invention for theproduction of crankcases, in particular cylinder bridge cooling systemsfor crankcases. It is furthermore conceivable to produce supportelements such as, for example, a cross member of a passenger car body bymeans of such a hollow cast salt core.

Furthermore, the method according to the invention enables the depictionof a highly productive, fully automated aluminum die casting process forcomplex aluminum die casting components with undercuts or hollowstructures which, up until now, have only been able to be produced bymeans of gravity casting. As a result of the hollow space being closedat least in the region of the filling opening by means of the saltmolding material introduced into the cavity, a fully automatedproduction process can be achieved for the production of such castingcores. At the same time, the advantages of aluminum die casting remainintact over aluminum gravity casting, sand and chill casting. Comparedto gravity, sand and chill casting, components are able to be producedconsiderably more cheaply and with a lower wall thickness by aluminumdie casting. In particular, it is possible to produce wall thicknessesin a range from 1.5 to 6 millimeters, in particular 2 millimeters.Furthermore, a particularly high dimensional stability is able to becreated with tolerances of approximately 0.1 percent. Furthermore,aluminum die casting components are able to be adjusted geometrically interms of stiffness by their hollow structure with the aid of hollow saltcasting cores and are suitable for vacuum die casting. Such componentsare therefore able to be heat treated for ductilization forcrash-relevant structural components. Furthermore, a salt core has theadvantage that it is soluble in water and purely organic, such that itis able to be cored with no emissions and is completely recyclable.

In the course of the method according to the invention, it isfurthermore possible to shape the casting core in such a way that thehollow body or the hollow space is completely closed, near-net-shaped,reproducible, dimensionally stable and sufficiently firm such that, forexample, a robot can automatically insert the produced casting core intoa correspondingly shaped aluminum die casting tool. Furthermore, wallthickness thickening of mounting openings, ridges etc. in the aluminumdie casting component can be achieved in a simple manner bycorresponding design of the casting core.

The still liquid salt molding material is, for example, a moltenmaterial consisting of a mixture of NaCl with Na₂CO₃. The proportion ofNaCl in the mixture is, for example, in a range from 30 inclusive to 70inclusive mass percent. In particular, the proportion of NaCl in themixture is 40 mass percent. In other words, the mass percentage of NaClin the mixture is in a range from 30 percent inclusive to 70 percentinclusive. In particular, the mass percentage of NaCl in the mixture is70 percent. The radical is Na₂CO₃. This means that the mass percentageof Na₂CO₃ is in a range from 30 inclusive to 70 inclusive percent, inparticular 60 percent.

A casting core also belongs to the invention, in particular for metalcasting, wherein it is provided according to the invention that thehollow space is closed on all sides by the hardened salt moldingmaterial. Advantageous embodiments of the method according to theinvention are to be considered as advantageous embodiments of thecasting core according to the invention and vice versa.

A further aspect of the invention relates to the use of a casting coreproduced according to the method according to the invention and/or acasting core according to the invention in a die casting method, inparticular in an aluminum die casting method.

It has been shown to be particularly advantageous when, in the contextof the method, at least one core mounting protruding from the hollowbody for mounting the casting core in a casting mold is produced fromthe salt molding material and by means of the mold. The hollow body ofthe casting core forms the actual salt core contour which is used toproduce hollow spaces of casting components. The core mounting protrudesfrom this actual salt core contour, i.e., from the hollow body. Thiscore mounting is used, for example, in the context of a die castingmethod, in particular in the context of an aluminum die casting method,to mount the casting core on or in a die casting mold. The core mountingproduced in the previously described manner enables a highly precise andautomated positioning of the casting core in a die casting tool, i.e.,in the die casting mold.

It can thereby be provided that the core mounting is formed to be solidat least in a partial region. It is thereby conceivable that the coremounting is formed to be completely solid. Alternatively, it is possiblethat the core mounting is hollow. As a result of the solid or at leastpartially solid design, the core mounting is particularly highly robust.

Simple accessibility into the hollow space, i.e., into the interior ofthe casting core, can be enabled by a hollow or partially solid coremounting, by means of which the casting core can be removed from theproduced casting component in a particularly simple manner.

The core mounting can be implemented as a fixed bearing in adimensionally stable manner and using casting technology in order toensure high dimensional stability of casting components to be producedby means of the casting core, in particular die casting components. Inother words, it is possible to depict a fixed bearing by means of thecore mounting, by means of which fixed bearing the casting core ismounted on the casting mold.

Furthermore, it is possible to implement the core mounting as a floatingbearing in a dimensionally stable manner and using casting technology inorder to be able to balance different thermal expansions of the castingcore and the casting tool. In other words, it is possible to depict afloating bearing by means of the core mounting, by means of whichfloating bearing the casting core is able to be mounted on the castingmold. The casting mold is formed, for example, from aluminum. As alreadydepicted, the salt molding material has a considerably higher thermalexpansion than aluminum. Different thermal expansions of the castingcore and the casting mold can thereby occur when casting or producing acasting component with the aid of the casting mold and the casting core.Since the casting core is mounted on the casting mold by means of atleast one floating bearing, these different thermal expansions can becompensated for as the casting core can be moved to a minor degreerelative to the casting tool.

Furthermore, it is possible for the core mounting to be used withoutmechanical processing for receiving in metal casting tools, inparticular die casting tools and preferably aluminum die casting tools.In other words, it is possible to produce not only the hollow body, butalso the core mounting, with high dimensional stability and high surfacequalities, such that the core mounting can be used to directly mount thecasting core on a casting mold. Mechanical processing of the coremounting is not provided and not required after its production.

Depending on the loading of the casting core during casting of thecasting component and/or depending on the processing conditions for thecasting core, the core mounting can be designed to be hollow or solid.Such a core mounting can, for example, be produced from an overflowfeeder during mold filling. In the case of the casting core, severalsuch core mountings are produced from respective overflow feeders duringmold filling if the mold has several overflows. Furthermore, it ispossible to produce such a core mounting on the sprue of the mold.Furthermore, it is possible to produce corresponding core mountings bycorresponding molding of the mold, in particular the cavity.

Further advantages, features and details of the invention arise from thefollowing description of preferred exemplary embodiments as well as withthe aid of the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic sectional view through a casting core according toa first embodiment which has a hollow body formed of a salt moldingmaterial having at least one hollow space which is delimited by thehardened salt molding material, wherein the hollow space is closed bythe hardened salt molding material on all sides;

FIG. 2 is a schematic sectional view through the casting core accordingto a second embodiment;

FIG. 3 is a schematic and perspective top view of the casting coreaccording to a third embodiment;

FIG. 4 is a schematic and perspective top view of the casting coredivided into two parts according to FIG. 3;

FIG. 5 is a schematic and perspective top view of an aluminum diecasting component which is produced with the aid of the casting coreaccording to a fourth embodiment;

FIG. 6 is a schematic and perspective front view of the casting coreaccording to the fourth embodiment; and

FIG. 7 is a schematic and perspective rear view of the casting coreaccording to the fourth embodiment.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a casting core 10 for metal casting in a schematicsectional view which can be used as a lost salt core in an aluminum diecasting method. The casting core 10 has a hollow body 12 which is formedby a hardened salt crust (crust 14). The salt crust 14 consists of ahardened salt molding material from which the casting core 10 isproduced.

It can be recognized from FIG. 1 that the casting core 10 or the hollowbody 12 has a hollow space 16 which is formed to be completely closed,i.e., on all sides. Furthermore, the casting core 10 has two coremountings 18, 20. In this case, the core mountings 18, 20 protrudelaterally from the hollow body 12 and serve to mount the casting core 10in the aluminum die casting tool on the die casting mold. An optional,moveable slide 22 can also be recognized from FIG. 1 and FIG. 2 which,for example, is used for the production of the casting core 10.

In a method for the production of a casting core 10, the salt moldingmaterial is firstly prepared in the form of a liquid molten salt. Themolten salt, for example, has a temperature from 30 to 80 degrees, inparticular from 50 to 80 degrees, above the solidus temperature. Themolten salt consists, for example, of a mixture of NaCl and Na₂Co₃. Themolten salt is preferably poured into a preferably heated mold, i.e.,into a casting mold. The mold is, for example, formed of steel. The moldis, for example, formed as a permanent steel mold. The temperature ofthe mold is preferably in a range from 250 degrees Celsius inclusive to350 degrees Celsius inclusive. In particular, the temperature of themold is 300 degrees Celsius. Furthermore, it is preferably provided thatthe casting core 10 is produced by gravity casting, low pressure diecasting or high pressure die casting.

The mold has, for example, two mold halves. Further dividers of this canbe implemented as slides, wherein, for example, the feeders and castingrunners provided for mold filling are located in a parting plane of thecasting core 10 formed as a salt casting part without forming undercutswhen molding the casting core 10.

The mold is filled with the molten salt without air inclusion, ifnecessary vacuum assisted and completely including the feeder andoverflows. The mold for the production of the casting core 10 has acavity which is filled with the molten salt via a filling openingleading into the cavity. The thermophysical properties of the moltensalt enable a crust-like, homogeneous solidification of the molten saltacross the whole surface of the cavity or the mold starting from themold in the direction of the hollow space 16, whereby an even,high-strength solidification layer results in the form of the crust 14.In other words, the molten salt introduced into the cavity or the moldis cooled, for example, for 30 to 180 seconds, whereby the firstly stillliquid salt molding material (molten salt) is hardened from the edge,i.e., from the mold inwards. The firm hollow body 12 is thereby formedby peripheral shell formation. In the later state arranged in thealuminum die casting tool, the casting core 10, in particular the hollowbody 12, is cast around with the firstly liquid casting material suchthat a hollow space of an aluminum die casting component is produced.

The salt mixture has a low thermal conductivity which reduces heatdissipation from the still liquid molten salt located in the hollowspace 16 into the comparatively colder casting mold with the increasingthickness of the crust 14, whereby the molten salt can be kept in liquidform for longer in the interior of the casting core 10, i.e., in thehollow space 16. The thickness of the crust 14, i.e., the wall thicknessof the hollow body 12, is determined by the resting time of the moltensalt in the casting mold.

In order to produce highly loaded core mounting points of the castingcore 10 during the subsequent aluminum die casting method when producingthe casting core 10 in a simple, highly dimensionally stable,reproducible and cost-effective manner, the casting system of the moldis used outside the hollow body 12 depicting the actual salt corecontour as a core mounting 18 or 20. The core mountings 18, 20 canthereby be filled to be at least almost solid, such that they have aparticularly high load capacity, in particular in comparison to theremaining contour of the casting core 10, since the remaining contour isonly formed by the crust 14.

The core mounting 18 is, for example, formed on the outlet feeder of thecasting mold and sized in such a way that the first cut on the castingcore 10 is solidified to be completely solid after crust formation hasbeen completed. The isolation effect of the crust 14 keeps the moltensalt in liquid form in the interior of the casting core 10 formed by thecrust 14. The crust formation is slowed down logarithmically by theresting time of the molten salt in the casting core 10.

It is preferably provided that the cross section of the feeder on theoutlet of the casting mold is sized in such a way that the peripheralshell formation completely freezes the first cut and seals the castingcore 10 and forms the core mounting 18.

Furthermore, it is preferably provided that the cross section of thefeeder on the inlet, i.e., on the inlet opening, is more than double thethickness of the crust 14, such that excess, still liquid molten saltcan be led away from the hollow space 16 via the filling opening, forexample can be poured out, wherein afterwards, the cut surface freezessuch that the hollow space 16 is sealed for die casting to form the coremounting 20. Further core mountings can optionally be produced in themolding direction of the aluminum die casting part in accordance withrequirements for strength and dimensional stability, such as for examplethe core mounting 18. Removing the casting core 10 from the mold andinserting the casting core 10 into the aluminum die casting tool takesplace, for example, by means of a robot, wherein the robot is able togrip the casting core 10, for example, on the core mountings 18, 20.Finally, the casting core 10 is inserted or put into the aluminum diecasting tool.

In other words, it can be provided that a still liquid first part of thesalt molding material introduced into the cavity of the mold is led awayfrom the hollow space 16 via the filling opening and the hollow space 16is closed at least in the region of the filling opening by means of astill liquid second part of the salt molding material introduced intothe cavity and located in the hollow space 16 by hardening this secondpart. The excess molten salt can therefore be poured out of the moldeither before or, in a time-controlled manner, after de-mold the saltcore by means of a firstly still remaining opening.

The still liquid salt molding material introduced into the cavity isused to close the cavity 16, forming a core mounting at the same time.This means that no processes following the production of the castingcore 10 are required to close the hollow space 16. In fact, the hollowspace 16 can be closed at least in the region of the filling openingwith the aid of the salt molding material which has already beenintroduced into the cavity.

Alternatively, it is possible that only the quantity of molten saltrequired for forming the crust 14 and the core mountings 18, 20 isfilled into the cavity and the filling opening is designed with asuitably created narrowing which enables the hot molten salt to bepoured in, prevents post feeding by freezing the molten material at thenarrow point and closes the filling opening. By moving the casting core10, wherein the casting core 10 can still be located in the mold oralready de-molded from the mold, the wall thickness can developed, forexample, in the region of the core mountings 18, 20 in addition to thecrust formation without the molten salt being able to escape from thehollow space 16.

In other words, it is possible to move the casting core 10 around atleast one axis, in particular around at least two axes which runperpendicularly to each other or around three axes which runperpendicularly to one another and thus three-dimensionally, while stillliquid molten salt is located in the hollow space 16, whereby the stillliquid molten salt located in the hollow space 16 is moved along wallsof the casting core 10 delimited by the hollow space.

The mechanically fixed crust 14 enables the molding of the casting core10 from the casting mold before shrinkage of the salt molding materialby cooling leads to damage to the casting core 10 on regions which arecritical for shrinkage such as ridges or wall strength cracks. With theaid of the residual melt which is still located in the core,mechanically more highly loaded regions or regions having lower crustformation inclination such as, for example, ridge peaks, can bethickened locally by means of suitable, three-dimensional movements ofthe casting core 10 outside the casting mold next to the core mountings18, 20, even in the subsequent aluminum die casting process, such thatthe casting core 10 can thereby be stiffened.

FIG. 2 shows the casting core 10 according to a second embodiment. Itcan be recognized from FIG. 2 that the casting core 10 according to thesecond embodiment differs from the casting core 10 according to thefirst embodiment in particular by the design of the core mountings 18,20.

FIG. 3 shows the casting core 10 according to a third embodiment. It canbe recognized from FIG. 3 that the casting core 10 according to thethird embodiment has ridges 24 which extend into the interior of thecasting core 10, i.e., into the hollow space 16. This is particularlyrecognizable from FIG. 4, in which the casting core 10 according to thethird embodiment is depicted in two parts. For example, the crust 14 is8 millimeters thick. The left core mounting 20 is formed by a closedoverflow, whereas the right core mounting 18 is formed by a closed,partially hollow sprue.

FIGS. 5 to 7 show the casting core 10 according to a fourth embodiment.Furthermore, an aluminum die casting component generally referred towith 26 is depicted by FIG. 5, the aluminum die casting component beingproduced by means of the casting core 10 according to the fourthembodiment.

1.-9. (canceled)
 10. A method for the production of a casting core, themethod comprising the steps of: preparing a mold which has at least onecavity and at least one filling opening which is fluidically connectedto the cavity; introducing a liquid, hardenable salt molding materialinto the cavity via the filling opening; and at least partial hardeningof the salt molding material introduced into the cavity to form a hollowbody produced from hardened salt molding material, the hollow bodyhaving at least one hollow space of the casting core which is delimitedby the hardened salt molding material, and wherein the hollow space ofthe casting core is closed on all sides by means of the salt moldingmaterial introduced into the cavity.
 11. The method according to claim10, wherein after the step of at least partial hardening, a still liquidfirst part of the salt molding material introduced into the cavity isled away from the hollow space via the filling opening and the hollowspace is closed at least in the region of the filling opening by meansof a still liquid second part of the salt molding material introducedinto the cavity by hardening of the second part of the hollow space. 12.The method according to claim 11, wherein a cross section of the fillingopening is more than double the wall thickness of the hardened saltmolding material which delimits the hollow space.
 13. The methodaccording to claim 10, wherein after closing the hollow space, thecasting core is moved around at least one axis, whereby a still liquidpart of the salt molding material located in the hollow space is spreadalong the hollow body and hardened.
 14. The method according to claim10, wherein at least one core mounting protruding from the hollow bodyis produced in a casting mold from the salt molding material and bymeans of the mold for mounting the casting core.
 15. The methodaccording to claim 14, wherein the core mounting is formed to be solidat least in a partial region.
 16. The method according to claim 10,wherein the casting core is cast to be near-net-shape with a tolerancein a range from 0.1 to 0.5 millimeters, and is removed from the mold.17. The method according to claim 10, further comprising using of theproduced casting core in a die casting method.
 18. The method accordingto claim 17, wherein the die casting method is an aluminum die castingmethod.
 19. The method according to claim 10, wherein the casting coreis for metal casting.
 20. A casting core comprising: a hollow bodyformed of a salt molding material, the hollow body having at least onehollow space which is delimited by the hardened salt molding material,and wherein the hollow space is closed on all sides by the hardened saltmolding material.
 21. The casting core according to claim 20, whereinthe casting core is used in a die casting method.
 22. The casting coreaccording to claim 21, wherein the die casting method is an aluminum diecasting method.
 23. The casting core according to claim 20, wherein thecasting core is for metal casting.